Not Your Average White Smoke Thread (2 Viewers)

[bsweaty]

I wouldn't be here if I haven't done my due diligence with the search bar and the "smoke" thread up top. 1993 Dyna 200 van, BII engine with a VE pump. I am fully stumped here, hoping someone here has experience. Engine has 35k miles on it roughly.

- The engine starts well, especially when warm. When cold(<40F or 5C) it may sputter for a moment and comes on around. Idles great. Appears normal.
- Engine appears to have all 80HP. The van goes 60mph, and with the weight and size... Appears to be accurate.
- Compression numbers are 415, 415, 420, 415. Looks great.
- Valve lash adjustment was done, valves weren't terribly far out of spec.
- Injectors have been replaced. Original injectors are being sent out for a cleaning. Injectors did not help the problem.
- No coolant is missing.
- Oil levels are not going up or going down.
- Timing mark on the injection pump matches the timing mark on the timing case. I have not attempted to adjust timing.
- Fuel filter has been replaced. I have not found a leak in the fuel lines.

Symptoms(I am happy to grab a video):
- Like many diesels, a little white smoke on start at idle, fades as it warms up.
- Decelerating after WOT(not at WOT), or holding throttle above 50% or more, the exhaust bellows out white smoke. Purely unburned fuel.
- No smoke on acceleration, no smoke at idle.

Is there a way that under this scenario, I could be losing/gaining timing or pop pressure at certain throttle? Is this the scenario where my return lines are clogged or not working properly? I have been scouring the internet looking for anything on this topic with no luck. Thanks for any help you can offer!

 

[relaxedcruiser]

Hi there,
rough guess is timing - without hearing and feeling the engine it is difficult to tell.
Has the problem occured one moment to the next or was it always like this ? Have you done anything with the engine prior experiencing the issue ?
The timing on the VE pump is also controlled by internal pump pressure. The return line banjo bolt close to the shut off solenoid has orifice in it - and most of them a screen filter too. It may be wort checking that as it alters the timing when clogged.

 

[Eurasiaoverland]

Smoke on deceleration is usually a sign of oil getting past worn/hardened valve stem seals. Does the engine use much oil? Does it smoke when engine-braking down a long hill?

All B engines are gear driven so almost impossible that injection timing could change unless the engine has been opened and the gears not installed correctly.

Load-based timing advance is controlled by internal pump pressure, but I doubt it would be enough to make a lot of smoke. I could be wrong though. You can verify base pump timing by measuring plunger stroke at TDC with a dial indicator and suitable extension - but if the factory scribe marks are aligned, I wouldn't bother.

 

[sodafeld1]

sorry if dumb question, definitely smells like fuel? really interesting, a vid would be good. If fuel, then it kind of seems like not enough pressure some how.

 

[Indestructible 47]

Whats the history of the IP? Notice any changes with fuel consumption? Oil consumption? If so over how many miles have you noticed it to burn x amount?

 

[Eurasiaoverland]

Everyone's judgement of colour is slightly different, and it seems you have previous experience with diesels, but usually white smoke, if it is derived from fuel, comes from completely unburned diesel (i.e. injectors working but engine not firing - you may have seen this with inoperative glow plugs on very cold starts). Overly rich fuelling causes black smoke in a hot, loaded engine, incomplete combustion when cold or idling looks more bluish to me (e.g. cold starts).

I'm assuming you don't have an exhaust brake? (I think only the bigger Dynas have them).

 

[bsweaty]

Everyone's judgement of colour is slightly different, and it seems you have previous experience with diesels, but usually white smoke, if it is derived from fuel, comes from completely unburned diesel (i.e. injectors working but engine not firing - you may have seen this with inoperative glow plugs on very cold starts). Overly rich fuelling causes black smoke in a hot, loaded engine, incomplete combustion when cold or idling looks more bluish to me (e.g. cold starts).

I'm assuming you don't have an exhaust brake? (I think only the bigger Dynas have them).

I'll cover both comments here. Zero oil consumption. I've put a few thousand miles on it since last oil change and the oil line is still good on the dip stick.

It does this sitting in the shop. Not just deceleration. There's something related to RPM and after throttle on WOT, or holding throttle above 50%. I'll post a video.

Interestingly, according to megazip this thing does have an exhaust brake. It's not an exhaust brake like one I have ever seen before. And I surely don't know how to operate it. I'll start looking for it! Back pressure could cause these symptoms... Right?

 

[bsweaty]

Whats the history of the IP? Notice any changes with fuel consumption? Oil consumption? If so over how many miles have you noticed it to burn x amount?

This thing currently has 35k miles. I believe those miles to be true. Zero oil consumption! I did a 3000 mile road trip this and it burned zero. I have never had the IP off. As far as I can tell, this thing hasn't been mucked with. I haven't found one aftermarket item on it.

The smoke is white, it burns my lungs and eyes. I can hold a rag up to the exhaust for a little while, smell it, and it's clearly diesel.

 

[bsweaty]

sorry if dumb question, definitely smells like fuel? really interesting, a vid would be good. If fuel, then it kind of seems like not enough pressure some how.

I'll get a video. It's 100% diesel. Burns my lungs and eyes. No oil consumption. 35k miles. I can hold a rag up to the exhaust for moments, smell it, it's clearly unburned fuel.

 

[bsweaty]

Hi there,
rough guess is timing - without hearing and feeling the engine it is difficult to tell.
Has the problem occured one moment to the next or was it always like this ? Have you done anything with the engine prior experiencing the issue ?
The timing on the VE pump is also controlled by internal pump pressure. The return line banjo bolt close to the shut off solenoid has orifice in it - and most of them a screen filter too. It may be wort checking that as it alters the timing when clogged.

I'll post a video up today. It's been like this since I have owned it. I haven't mucked with anything. The van does 60mph, so I've always assumed it's up to power for what the engine is supposed to do.

I'll definitely check the screen filter! Great idea, i'll also make sure fuel is making it all the way back to the fuel tank on return.

 

[bsweaty]

Everyone's judgement of colour is slightly different, and it seems you have previous experience with diesels, but usually white smoke, if it is derived from fuel, comes from completely unburned diesel (i.e. injectors working but engine not firing - you may have seen this with inoperative glow plugs on very cold starts). Overly rich fuelling causes black smoke in a hot, loaded engine, incomplete combustion when cold or idling looks more bluish to me (e.g. cold starts).

I'm assuming you don't have an exhaust brake? (I think only the bigger Dynas have them).

I definitely have an exhaust brake. However I have yet to figure out how to turn it on or off. I don't see a handle or a button anywhere around my dash to enable it?

 

[bsweaty]

 

[Eurasiaoverland]

I definitely have an exhaust brake. However I have yet to figure out how to turn it on or off. I don't see a handle or a button anywhere around my dash to enable it?

View attachment 3575437

View attachment 3575439

Time to learn Japanese!

Interesting condition, I've never seen anything like that smoke. Without your description I would have said that is unburned oil. The engine is clearly running nicely - if the pump was over-fuelling on lift-off you'd get the revs hanging, which it clearly isn't doing. If the injectors have been serviced, then we can rule out those leaking. If the pump was somehow so out of phase that it was injecting during the exhaust stroke, then surely it would not run well (or at all...)

I think that exhaust brake is worth checking.. I have zero experience with them, but it seems like there is a banjo bolt on it which suggests it could put oil into the exhaust.

 

[bsweaty]

Time to learn Japanese!

Interesting condition, I've never seen anything like that smoke. The engine is clearly running nicely - if the pump was overfuelling on lift-off you'd get the revs hanging, which it clearly isn't doing. If the injectors have been serviced, then we can rule out those leaking. If the pump was somehow so out of phase that it was injecting during the exhaust stroke, then surely it would not run well.

I think that exhaust brake is worth checking...

I think you are right! That's where I will look next... That and the return lines from the injectors. I can imagine back pressure can cause issues, and too much pressure in the IP as well.

Thanks a ton!

 

[bsweaty]

Time to learn Japanese!

Interesting condition, I've never seen anything like that smoke. Without your description I would have said that is unburned oil. The engine is clearly running nicely - if the pump was over-fuelling on lift-off you'd get the revs hanging, which it clearly isn't doing. If the injectors have been serviced, then we can rule out those leaking. If the pump was somehow so out of phase that it was injecting during the exhaust stroke, then surely it would not run well (or at all...)

I think that exhaust brake is worth checking.. I have zero experience with them, but it seems like there is a banjo bolt on it which suggests it could put oil into the exhaust.

I haven't been able to figure out how the exhaust brake works. There's a vacuum line to it as well as a wire. However I did just unbolt it and verified it is open. I also checked the return banjo on IP and it seems to be working as expected. I didn't see any fuel come out specifically, but the inside of the banjo and lines are clean and appears that fuel has traveled back through.

I am pretty stumped here. I did turn my fuel down 1/4 turn and it helped with smoke immensely, however throttle response is sluggish.

 

[bsweaty]

Time to learn Japanese!

Interesting condition, I've never seen anything like that smoke. Without your description I would have said that is unburned oil. The engine is clearly running nicely - if the pump was over-fuelling on lift-off you'd get the revs hanging, which it clearly isn't doing. If the injectors have been serviced, then we can rule out those leaking. If the pump was somehow so out of phase that it was injecting during the exhaust stroke, then surely it would not run well (or at all...)

I think that exhaust brake is worth checking.. I have zero experience with them, but it seems like there is a banjo bolt on it which suggests it could put oil into the exhaust.

I do have a pump timing gauge. I believe next step is to verify actual pump timing.

 

[sodafeld1]

I do have a pump timing gauge. I believe next step is to verify actual pump timing.

that's what i reckon it needs. aren't they huge expensive fandangled things which measure fuel delivery per injector outlet with the pump installed, requiring re calibration every couple of years?!

I use to have an el cheapo injector tester, it gummed up from what I thought was good clean fresh fuel pretty quickly. Just a few months to a year..

You know heaps more than me, enjoying your adventure. Diesel engine problems are like logical puzzles usually. It is getting too much fuel it seems.

 

[bsweaty]

that's what i reckon it needs. aren't they huge expensive fandangled things which measure fuel delivery per injector outlet with the pump installed, requiring re calibration every couple of years?!

I use to have an el cheapo injector tester, it gummed up from what I thought was good clean fresh fuel pretty quickly. Just a few months to a year..

You know heaps more than me, enjoying your adventure. Diesel engine problems are like logical puzzles usually. It is getting too much fuel it seems.

thanks for chiming in! for checking pump timing, not in this case. VE or rotary style pumps are easy to check the plunger depth. i haver a VE 12v Cummins I've been wrenching on for years, it feels familiar on this toyota. check the video out in this thread:

https://forum.ih8mud.com/threads/3b-injection-pump-install-tips.1224257/

I've played with the fuel screw all the way from almost stalling at idle to a robust throttle response. The patterning is the same with the smoke across the board, just the amount of smoke changes. I'm assuming the injectors are popping late causing a lack of combustion. Getting the IP in time seems to be the best way forward.

 

[sodafeld1]

I'm assuming the injectors are popping late causing a lack of combustion. Getting the IP in time seems to be the best way forward.

exactly what I am guessing

 

[sodafeld1]